As fires rage across large parts of Indonesia’s Riau province, authorities have begun cloud seeding to bring rain and ease the warmth.
These weather modification activities have turn out to be a key a part of the broader firefighting strategy, assisting firefighters on the bottom and providing much-needed assistance to communities battling smoke and flames.
A growing crisis
In recent weeks, Riau Province in Sumatra has been facing intense fires, especially in peatlands. These fires are extremely difficult to manage because peat soil can burn deep below the surface and the flames are fueled by dry conditions.
The regional disaster management agency has declared a state of emergency as hot spots proceed to spread in areas corresponding to Bengkalis, Siak, Pelalawan and Dumai.
Dry weather and high winds made conventional firefighting efforts extremely difficult, and crews struggled to extinguish the flames using only water bombing and ground teams.
Peat fires also pose serious environmental and health risks. Smoke from burning forests and peat can spread over long distances, worsening air quality and affecting the health of civilians and travelers throughout the region.
The urgency of the situation has prompted authorities to look beyond traditional firefighting methods and switch their attention to atmospheric intervention to more quickly alleviate the crisis.
What is cloud seeding and the way does it work?
Cloud seeding is a type of weather modification intended to encourage rainfall. The technique involves dispersing particles within the atmosphere that act as nuclei around which moisture from existing clouds can condense and fall as rain.
These particles are sometimes substances corresponding to sodium chloride – table salt – or silver iodide, depending on conditions and availability. The goal will not be to create clouds from a transparent sky, but to extend the rain potential of existing clouds.
In the case of Riau, authorities took advantage of appropriate cloud formation within the region to seed clouds from the air.
This approach allows rainfall to be induced in fire-affected areas and adjoining landscapes. By increasing rainfall, cloud seeding goals to smother dry vegetation, replenish soil moisture and help firefighters contain peat and forest fires more quickly.
Implementation
The weather modification operation in Riau is led by the National Disaster Mitigation Agency (BNPB) in cooperation with regional disaster response teams.
The Cessna 208B Grand Caravan aircraft was deployed from Roesmin Nurjadin Air Force Base in Pekanbaru to conduct the cloud seeding mission. During the operation, the aircraft disperses sodium chloride into cloud layers over the targeted areas.
During the initial phase of the mission, BNPB provided roughly 8.5 tons of salt for sowing. The local authority has since received a further 15 tonnes of salt to further strengthen ongoing efforts.
Missions focused particularly on coastal and fire-prone areas, where rainfall is most urgently needed to mitigate the consequences of hot spots and rehydrate dry peatlands.
Teams from the regional disaster management agency – together with military personnel, police, forest fire brigades and area people members – work together to support cloud seeding flights and ground-based firefighting efforts.
Early results and wider impacts
Early reports from the campaign indicate that cloud seeding helped encourage rainfall, relieve pressure on firefighting efforts and provides ground crews a bonus in controlling the fires.
Although cloud seeding can only work if clouds exist already to seed, targeted operations have shown promise in increasing local rainfall in critical areas.
Rain attributable to cloud seeding not only helps extinguish fires, but in addition helps to re-wetting peatlands, which is crucial to reducing the likelihood of re-ignition once fires have been suppressed.
Moist peat soils are less more likely to smolder and re-ignite, making prolonged rainfall a key defensive element in long-term fire management.
Challenges and considerations
While cloud seeding is a priceless tool within the fight against wildfires, it will not be a stand-alone solution. The success of cloud seeding relies on the presence of clouds and sufficient humidity within the air, which implies they can’t generate rain under clear skies.
Moreover, the rain produced will not be at all times intense or extensive enough to completely extinguish large fires by itself.
Officials proceed to mix cloud seeding with traditional firefighting resources, corresponding to helicopters to drop water bombs, ground fire crews, patrols to forestall latest disease outbreaks, and public health measures to guard communities affected by haze and smoke.
